Hi all,
I've been running the following script to get the top 4 processes on a
list of some of the hosts on our network:
#!/bin/tcsh -f
set stations = (list of hosts)
foreach station ($stations)
echo "##### $station #####"
rsh $station "top n1 b | head -14 | tail -4"
echo ""
end
# The End!
This actually worked fine, but a little slow, since each host is
accessed after the other, rather than in parallel.
Question 1 - can this be made parallel in tcsh? bash?
Anyway, I decided to try to do it faster in Perl by using "fork":
#!/usr/bin/perl
use strict;
use warnings;
use Proc::Daemon;
my @hosts = qw (list of hosts);
for my $host (@hosts) {
my $pid;
if ($pid = Proc::Daemon::Fork) {
} elsif (defined $pid) {
print "\n##### $host #####\n" . `rsh $host top n1 b | head -14 |
tail -4` . "\n";
exit 0;
} else {
warn "Can't fork for host $host: $!\n";
}
}
# The End!
This worked fine, as fast as I expected. However, here there were 2
small problems:
Question 2: The order of the reported stations was random. I guess I
should have expected this (due to the nature of fork), but is there a
way to get the outputs in the same order as the list of hosts?
Question 3: After the last output finishes I have to wait a few
seconds (exact time depends on the number of hosts) before the
terminal is "released" and I can type in it again. This BTW does not
happen if I replace the "top" command by for example 'uname -a'. Why
does this happen and how can I stop it from happening?
All the hosts are Linux hosts, I'm running perl 5.8.0.
Thanks in advance,
--
Offer Kaye